A screen is at a distance
D=80 cm from a diaphragm having two narrow slits
S1 and
S2 which are
d=2 mm apart. Slit
S1 is covered by a transparent sheet of thickness
t1=2.5 μm and slit
S2 is covered by another sheet of thickness
t2=1.25 μm as shown in figure
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1293593/original_9.qstn.png)
Both sheets are made of same material having refractive index
μ=1.40. Water is filled in the space between diaphragm and screen. A monochromatic light beam of wavelength
λ=5000 ˙A is incident normally on the diaphragm. Assuming intensity of beam to be uniform, calculate ratio of intensity at
C to the maximum intensity of interference pattern obtained on the screen
(μw=43).